JP7049149B2 - How to make wings - Google Patents

Description

The present invention relates to a method for manufacturing a wing.

The metal injection molding method (hereinafter, appropriately referred to as MIM) is widely used for manufacturing mechanical parts because of its high productivity and dimensional accuracy. MIM is to knead metal and alloy powder and organic binder, and inject the kneaded compound into a mold to create a molded product with a desired shape, remove the organic binder from the molded product, and sinter. This is a processing method for obtaining a sintered body having a predetermined shape.

Patent Document 1 describes a method for manufacturing a turbine wheel to which MIM is applied. In the method for manufacturing a turbine wheel described in Patent Document 1, after a sintered body is obtained by MIM, hot isostatic pressing (hereinafter, appropriately referred to as HIP treatment), cutting and pressing are performed. This makes it possible to manufacture a turbine wheel with a desired sintering density and dimensional accuracy.

Japanese Unexamined Patent Publication No. 2011-174096

Here, since sintering and HIP treatment in MIM are processes in which a heat load exceeding 1000 ° C. is applied to the product, the product may be deformed due to a temperature change. Further, when a member having a thin thickness is manufactured, there is a problem that deformation due to thermal strain is particularly likely to occur.

The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a method for manufacturing a wing capable of manufacturing a wing with high dimensional accuracy.

The present invention is the molding process of injecting metal particles toward a mold to form a wing by metal injection molding, and the mold of a jig which is divided into at least two and the shape of the wing is formed inside. It is characterized by comprising a jig mounting step of sandwiching the blade on the surface on which the blade is formed and attaching the jig to the blade, and a heat treatment step of heat-treating the blade to which the jig is attached.

According to this configuration, it is possible to prevent the temperature of the thin-walled portion from dropping by covering the blade with a jig, and it is possible to suppress the generation of a temperature difference in the blade when heat treatment is performed in the heat treatment step, and the heat generated in the blade can be suppressed. The stress can be relaxed, the deformation of the blade due to thermal stress can be suppressed, and the blade with high dimensional accuracy can be manufactured.

Further, in the jig mounting step, a holding portion that holds the jig in the direction of sandwiching the wing is attached to the jig while the jig sandwiches the wing, and in the heat treatment step, the holding portion holds the wing. It is preferable to perform the heat treatment while being attached to the jig.

According to this configuration, even if the wing is deformed in the molding process, the jig can be attached to the wing, and the wing can be heat-treated while the force is applied so that the wing returns to the shape of the design dimension. The wing can be corrected to the design dimensions, and the dimensional accuracy of the wing can be improved.

Further, the metal particles are preferably formed of stainless steel, a Ni-based alloy, a titanium alloy, and a titanium-aluminum alloy.

According to the present invention, it is possible to manufacture a wing with high dimensional accuracy.

FIG. 1 is an outline view showing a moving blade of a turbomachine manufactured by the blade manufacturing method according to the present embodiment. FIG. 2 is an example of a flowchart showing a method for manufacturing a wing according to the present embodiment. FIG. 3 is a cross-sectional view showing a jig and a moving blade in the jig mounting process of the blade manufacturing method according to the present embodiment. FIG. 4 is a cross-sectional view showing a jig and a moving blade in the jig mounting process of the blade manufacturing method according to the present embodiment.

Hereinafter, embodiments according to the present invention will be described in detail with reference to the drawings. The present invention is not limited to this embodiment. In addition, the components in the following embodiments include those that can be easily replaced by those skilled in the art, or those that are substantially the same. Further, the components described below can be appropriately combined, and when there are a plurality of embodiments, each embodiment can be combined.

FIG. 1 is an outline view showing a moving blade 10 of a turbomachine manufactured by the blade manufacturing method according to the present embodiment. FIG. 2 is an example of a flowchart showing a method for manufacturing a wing according to the present embodiment. 3 and 4 are cross-sectional views showing a jig and a moving blade in the jig mounting process of the blade manufacturing method according to the present embodiment, respectively.

The blade manufactured by the blade manufacturing method of the present embodiment is applied to, for example, the moving blade 10 of a turbomachine. In this embodiment, it is applied to the moving blade 10 of the turbomachine, but it is not particularly limited and may be applied to any other blade. For example, the blade manufacturing method of the present embodiment may be applied to the rotor blades / stationary blades of an aircraft engine, the rotor blades of an industrial gas turbine, and the rotor blades of a steam turbine. First, prior to the description of the method for manufacturing the moving blade 10, the jig 20 used for manufacturing the moving blade 10 and the moving blade 10 will be described with reference to FIGS. 1 and 3.

The rotor blade 10 includes a blade root portion 12, a blade portion 14, and a shroud 16. The moving blade 10 is a blade fixed to the rotating shaft of the turbo machine via a rotor disk. The material of the rotor blade 10 is a titanium alloy, but the material is not limited thereto. The material of the rotor blade 10 may be, for example, a nickel alloy.

The blade root portion 12 is formed at the end portion of the rotor blade 10 on the rotation axis side 18. Here, the rotary shaft side 18 is the side on which the rotary shaft of the rotor blade 10 is installed. As shown in FIG. 1, the wing root portion 12 has a shape in which a plurality of irregularities are formed. The blade root portion 12 is fitted into, for example, an opening that matches the uneven shape of the blade root portion 12 formed on the outer periphery of the rotor disk. That is, the blade root portion 12 is fixed to the rotor disk.

In the blade portion 14, one end of the rotation shaft side 18 is connected to the blade root portion 12, and the other end is connected to the shroud 16. The wing portion 14 has a thin plate shape.

The shroud 16 is formed at the end of the rotor blade 10 in the direction opposite to the rotation axis side 18. The shroud 16 is a member that comes into contact with the shroud of the adjacent rotor blade to fix the rotor blade 10 and suppress the vibration of the rotor blade 10.

The jig 20 has a dorsal jig 22 and a ventral jig 24. As shown in FIG. 3, the jig 20 is a mold in which the shape of the design dimension of the wing portion 14 is formed inside. The jig 20 can be divided into a dorsal jig 22 and a ventral jig 24. The jig 20 is not limited to the dorsal jig 22 and the ventral jig 24, although the jig 20 can be divided into the dorsal jig 22 and the ventral jig 24. The jig 20 may be divided into three or more members. The outer shape of the cross section of the jig 20 shown in FIG. 3 is rectangular, but is not limited to this. The outer shape of the cross section of the jig 20 may be polygonal, circular or elliptical.

The dorsal jig 22 is a type attached to the dorsal surface of the wing portion 14. Here, the dorsal surface of the wing portion 14 is a negative pressure surface of the wing portion 14. The material of the dorsal jig 22 is alumina ceramics, but the material is not limited thereto. The back jig 22 may be made of a material having a hardness higher than that of the moving blade 10 at least in the temperature range applied in the heat treatment step of the blade manufacturing method. The dorsal jig 22 has a coating 26 formed on the surface in contact with the moving blade 10. The coating layer 26 is, for example, a sprayed film of yttrium ceramic, but is not limited thereto. The coating layer 26 may be formed of a material having a strength higher than that of the moving blade 10 and a low reactivity with the moving blade, at least in the temperature range applied in the heat treatment step of the blade manufacturing method.

The ventral jig 24 is a type attached to the ventral surface of the wing portion 14. Here, the ventral surface of the wing portion 14 is the surface on the side where the wing portion 14 receives the wind. The material of the ventral jig 24 is nickel alloy, but the material is not limited to this. The ventral jig 24 may be made of a material having a hardness higher than that of the moving blade 10 at least in the temperature range applied in the heat treatment step of the blade manufacturing method. The ventral jig 24 has an insulator layer 28 formed on a surface in contact with the moving blade 10. The insulator layer 28 is, for example, a ceramic sprayed film, but is not limited thereto. The insulator layer 28 may be formed of an insulating material having a hardness higher than that of the rotor blade 10 at least in the temperature range applied in the heat treatment step of the blade manufacturing method.

Here, it is preferable that the dorsal jig 22, the ventral jig 24, and the ventral jig 24 are made of a material having a linear expansion coefficient close to that of the titanium-aluminum alloy, which is the material used for the rotor blade 10. Here, the fact that the coefficient of linear expansion is close is Inconel 903, and the numerical values thereof are shown in Table 1. Since molding is possible even if the coefficient of linear expansion differs depending on the product shape, the material used for the jig may be a ceramic material or carbon.

Next, the manufacturing method of the above-mentioned rotor blade 10 will be described with reference to FIGS. 2, 3 and 4. As shown in FIG. 2, in the method for manufacturing a blade in the present embodiment, a molding step S1, a jig mounting step S2, and a heat treatment step S3 are sequentially performed.

In the molding step S1, the moving blade 10 is molded using MIM. Specifically, the metal particles and the binder are sufficiently kneaded to prepare a compound. Here, the metal particles are, for example, titanium-aluminum alloy powder. Here, the binder is, for example, paraffin wax. Next, using an injection molding machine equipped with a mold, the compound is ejected toward the mold, and the static mobile phone is injection-molded. Next, the molded product is heated to a temperature range in which the binder volatilizes, and the binder is removed from the molded product (hereinafter, removing the binder is appropriately referred to as degreasing). The degreasing may be performed by immersing the molded product in a solvent in which the binder can be dissolved. Next, the molded body is heated at a predetermined sintering temperature to sinter the molded body. Before degreasing the molded body, an operation of removing linear convex traces (parting lines) generated by injection molding may be executed. Here, the moving blade 10 is formed of, for example, a titanium-aluminum alloy. The moving blade 10 may be made of stainless steel, a Ni-based alloy, or a titanium alloy.

In the jig mounting step S2, the jig 20 is mounted on the blade portion 14 of the moving blade 10 as shown in FIG. Specifically, the wing portion 14 is sandwiched between the dorsal side jig 22 and the ventral side jig 24, and the jig 20 is attached to the wing portion 14. That is, the circumference of the wing portion 14 is covered with the space inside the jig 20. The internal space has a shape that follows the design shape of the wing portion 14. Here, when the wing portion 14 is deformed in the molding step S1 and the shape of the jig 20 and the shape of the wing portion 14 are deviated from each other by a predetermined value or more, the jig portion 14 has a jig as shown in FIG. After attaching 20, the jig 20 is pressed by the pressing portion 30. Specifically, the wing portion 14 is sandwiched between the dorsal jig 22 and the ventral jig 24, and the dorsal jig 22 and the ventral jig 24 are pressed by the pressing portion 30 and moved from the ventral side and the dorsal side. A force is applied to the jig 20 so as to press the wing 10, and the jig 20 is attached to the wing portion 14. Here, the holding portion 30 is, for example, a clamp and a vise. When the deformation of the wing portion 14 is large as described above, a force is applied to the jig 20 by the pressing portion 30, and the wing portion 14 is housed in the jig 20 as shown in FIG.

In the heat treatment step S3, the moving blade 10 to which the jig 20 is attached is heat-treated. The heat treatment is, for example, a HIP treatment. Here, the HIP treatment is a heat treatment in which a pressure of 10 MPa to 200 MPa and a heat load exceeding 1000 ° C. are applied to the object to be treated under an argon atmosphere. The heat treatment in the heat treatment step S3 is a HIP treatment, but the heat treatment is not limited to this. The heat treatment in the heat treatment step may be a vacuum heat treatment, a normal pressure heat treatment, an atmospheric heat treatment in which heating is performed in an inert gas atmosphere, or a hot press heat treatment in which heating is performed in a state of being pressurized from one direction. Here, the heat treatment is performed at a temperature lower than that of the sintering process in the molding step S1. It is necessary to select heat treatment conditions from various conditions in order to obtain desired mechanical properties, but as a typical heat treatment, it is preferable to hold the heat treatment at a temperature of 800 ° C. or higher and 1200 ° C. or lower for 10 to 100 hours.

In the method for manufacturing a wing according to the present embodiment, a jig 20 which is a mold in which the shape of the wing portion 14 is formed inside is attached to the wing portion 14 in the jig attachment step S2, and heat treatment is performed in the heat treatment step S3. This makes it possible for the jig 20 to cover the wing portion 14, and by using the jig 20, the difference in cooling speed depending on the position of the wing portion 14 in the heat treatment step S3 can be reduced, and the heat treatment step S3 It is possible to suppress the occurrence of a temperature difference in the wing portion 14. Specifically, the outside of the jig 20 becomes an external space, and both the thick portion and the thin portion of the wing portion 14 dissipate heat through the jig 20, so that the temperature can be lowered on average. As a result, the thermal stress generated in the blade portion 14 can be relaxed, and the deformation of the blade due to the thermal stress can be suppressed. In this way, the deformation of the blade can be suppressed and the cooling can be averaged, so that the blade with high dimensional accuracy can be manufactured.

Further, when the blade is made of a titanium-aluminum alloy that is easily deformed by a temperature change, it is possible to manufacture a blade with particularly high accuracy. By forming the wing from the titanium-aluminum alloy, it is possible to manufacture a wing that is lighter in weight and stronger than when the nickel alloy is applied to the material of the wing.

Further, in the method for manufacturing a wing of the present embodiment, when the wing portion 14 is deformed in the molding step S1, the wing portion 14 is provided between the back side jig 22 and the ventral jig 24 in the jig mounting step S2. The jig 20 is attached to the wing portion 14 by sandwiching the back jig 22 and the ventral jig 24 with the pressing portion 30 and applying a force to the jig 20 so as to press the moving wing 10 from the ventral side and the dorsal side. In the heat treatment step S3, the blade portion 14 to which the jig 20 is attached is heat-treated. As a result, even if the wing portion 14 is deformed in the molding step S1, the wing portion 14 can be heat-treated in a state where the wing portion 14 is returned to a shape closer to the design dimension, and the wing portion 14 is corrected to the design dimension. Therefore, the dimensional accuracy of the wing portion 14 can be improved.

Further, in the method for manufacturing a wing of the present embodiment, in the jig mounting step S2, the jig 20 in which the insulator layers 26 and 28 are formed in the portions in contact with the wing portion 14 is attached to the wing portion 14. This makes it possible to interpose an insulator between the wing portion 14 and the jig 20, and electrically insulate the wing portion 14 and the jig 20 from each other. It is possible to prevent the electric corrosion that occurs during the period, and it is possible to manufacture a higher quality wing.

Further, in the method for manufacturing a blade of the present embodiment, the moving blade 10 is molded by using MIM in the molding step S1. This makes it possible to manufacture the rotor blade 10 with higher dimensional accuracy as compared with the manufacturing by casting, and it is possible to improve the productivity and reduce the manufacturing cost.

10 Rotor blade 12 Root blade 14 Wing 16 Shroud 18 Rotating shaft side 20 Jig 22 Dorsal jig 24 Ventral jig 26, 28 Insulator layer 30 Holding part

Claims (4)

A method for manufacturing a wing having a wing root and a wing.
The molding process of injecting metal particles toward a mold to form a wing by metal injection molding,
The shape of the wing was formed inside , including a dorsal jig attached to the dorsal side of the wing portion and a ventral jig attached to the ventral side of the wing portion, which were divided into at least two parts. A jig mounting process in which the blade is sandwiched between the surfaces of the jig that is the mold on which the mold is formed, and the jig is attached to the blade.
A method for manufacturing a wing, which comprises a heat treatment step of applying a heat treatment to the wing to which the jig is attached. In the jig mounting step, with the jig sandwiching the wing, a holding portion that presses the jig in the direction of sandwiching the wing is attached to the jig.
The method for manufacturing a wing according to claim 1, wherein the heat treatment step is performed by performing the heat treatment in a state where the holding portion is attached to the jig. The method for manufacturing a wing according to claim 1 or 2, wherein the metal particles are made of a titanium-aluminum alloy. The method for manufacturing a wing according to any one of claims 1 to 3, wherein the jig has an insulator layer formed on a surface in contact with the wing.

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